1. Field of the Invention
The present invention relates to devices providing supply voltages.
2. Discussion of the Related Art
In the present patent application, the terminology &lt;&lt;high voltage&gt;&gt; refers to an incoming voltage corresponding, for example to a rectified main voltage. A high voltage may have a peak value of approximately a few hundred volts. &lt;&lt;Low voltage&gt;&gt; refers to a voltage which is lower than the high voltage, for example a control or supply voltage for electronic circuits, i.e., a voltage ranging from a few volts to a few tens of volts.
Generally, in the state of the art, when it is desired to simultaneously provide d.c. voltages to a load and to various circuits for controlling the load, a first supply circuit is provided for the load and a second supply circuit is provided for the control circuits. A drawback of such a double circuit is the duplication of circuitry and the fact that each circuit has distinct ohmic losses.
Transformers including a plurality of secondary windings are also used. Such transformers have the drawback of requiring additional windings and, therefore, of being cumbersome and expensive.